80 lb Concrete Bag Coverage Chart
Use this 80 lb concrete bag coverage chart for 2, 3, 4, 5, and 6 inch thickness, sq ft coverage, bag counts, pallet checks, and waste.
An 80 lb concrete bag commonly yields about 0.60 cubic feet. That means one bag covers about 2.4 sq ft at 3 in thick, 1.8 sq ft at 4 in thick, and 1.2 sq ft at 6 in thick before waste.
Use the Concrete Bag Calculator for exact whole-bag counts, the Concrete Quote Reviewer for ready-mix comparisons, and the Concrete Proposal Kit for material line items.
Competitor pages such as ConcreteCalculatorMax's concrete bag coverage and yield guide and ConcreteCalculator.pro's concrete bag calculator cover broad bag math. This page answers the 80 lb coverage question directly.
Quick answer
| Thickness | One 80 lb bag covers | 100 sq ft before waste | 100 sq ft with 10% waste |
|---|---|---|---|
| 2 in | about 3.6 sq ft | 28 bags | 31 bags |
| 3 in | about 2.4 sq ft | 42 bags | 46 bags |
| 4 in | about 1.8 sq ft | 56 bags | 62 bags |
| 5 in | about 1.4 sq ft | 70 bags | 77 bags |
| 6 in | about 1.2 sq ft | 84 bags | 92 bags |
Confirm the yield printed on the exact 80 lb bag before buying.
This coverage chart is a planning aid only. For structural thickness, soil, reinforcement, frost, permits, or load-bearing requirements, confirm the slab design with a qualified local professional.
Formula
coverage sq ft = 0.60 / (thickness inches / 12)
bags = total sq ft / coverage sq ft
Then add waste and round up.
Common project checks
| Project | Planning note |
|---|---|
| 6x6 slab at 4 in | About 20 bags with 10% waste. |
| 8x8 slab at 4 in | About 40 bags with 10% waste. |
| 10x10 slab at 4 in | About 62 bags with 10% waste. |
| 20x20 slab at 4 in | About 247 bags with 10% waste. |
For slab-specific pages, review Concrete Bags for 6x6 Slab and Concrete Bags for 20x20 Slab.
Pallet warning
A common planning pallet of 42 bags yields about 25.2 ft3, or about 0.93 yd3. At 4 in thick, that covers about 76 sq ft before waste. If your project needs more than one pallet, compare ready-mix delivery before buying.
Use the Concrete Bag Pallet Weight Guide for transport planning.
FAQ
How much does an 80 lb bag cover at 4 inches?
About 1.8 sq ft before waste, using a common yield of 0.60 ft3.
How much does an 80 lb bag cover at 3 inches?
About 2.4 sq ft before waste.
How much does an 80 lb bag cover at 6 inches?
About 1.2 sq ft before waste.
How many 80 lb bags cover 100 sq ft at 4 inches?
About 56 bags before waste, or about 62 bags with 10% waste.
Should I use 80 lb bags for a large slab?
Maybe, but pallet-scale orders are heavy and slow to mix. Compare ready-mix delivery, labor, and finish timing first.
Next step
Use this chart as a quick check, then run the exact job through the Concrete Bag Calculator and compare with ready-mix in the Concrete Quote Reviewer.
Quote planning next step
Turn this guide into a concrete buying check
Run the matching calculator, then compare ready-mix, bagged concrete, delivery fees, access needs, and quote gaps before you buy materials or approve a contractor number.